Touch sensor, electronic paper display panel and electronic paper display apparatus

ABSTRACT

A touch sensor configured to sense a touch object is provided. The touch sensor includes a sensing device and a sensing circuit. The sensing device includes a substrate, a sensing electrode, a sensing common electrode and a shielding layer. The sensing electrode and the sensing common electrode are disposed on the substrate. The shielding layer is disposed on the sensing electrode and the sensing common electrode. The sensing circuit is electrically connected to the sensing device. The sensing circuit includes a resistor device. A relaxation frequency of a relaxation signal of the touch sensor is determined according to a resistance of the resistor device and/or a parasitic resistance of the sensing device. A pulse difference of the relaxation signal is changed by the touch object. The touch object is a conductor. An electronic paper display panel and an electronic paper display apparatus including the foregoing touch sensor are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 107116396, filed on May 15, 2018. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a sensor, a display panel and a displayapparatus, and particularly relates to a touch sensor, an electronicpaper display panel and an electronic paper display apparatus.

Description of Related Art

In recent years, since an electronic paper display apparatus hasadvantages of light and slim, durable, low power consumption that meetsthe requirement of energy saving and environmental protection, etc., itis widely applied to electronic readers (for example, electronic books,electronic newspapers) or other electronic devices (for example,electronic tags). On the other hand, if the electronic paper displayapparatus may have a touch sensing function, it may provide an intuitiveinput method to the user to improve user's experience.

Generally, a touch sensor has to be exposed to air, and an internallayered structure thereof should not include, for example, an Indium TinOxide (ITO) conductive thin film or other similar conductive layer, soas to avoid covering other layered structures to cause a shieldingeffect and result in a fact that the touch sensor cannot implement atouch sensing operation. However, a panel of the electronic paperdisplay apparatus generally includes the ITO conductive thin film orother similar conductive layer. When the touch sensor is integrated withthe panel of the electronic paper display apparatus, the touch sensor isliable to unable to implement the touch sensing operation.

SUMMARY OF THE INVENTION

The invention is directed to touch sensor, an electronic paper displaypanel and an electronic paper display apparatus, which include ashielding layer to provide a touch sensing function.

The invention provides a touch sensor adapted to sense a touch object.The touch sensor includes a sensing device and a sensing circuit. Thesensing device includes a substrate, a sensing electrode, a sensingcommon electrode and a shielding layer. The sensing electrode and thesensing common electrode are disposed on the substrate. The shieldinglayer is disposed on the sensing electrode and the sensing commonelectrode. The sensing circuit is electrically connected to the sensingdevice. The sensing circuit includes a resistor device. A relaxationfrequency of a relaxation signal of the touch sensor is determinedaccording to a resistance of the resistor device and/or a parasiticresistance of the sensing device. A pulse difference of the relaxationsignal is changed by the touch object, where the touch object is aconductor.

In an embodiment of the invention, the touch sensor is operated in anoperation frequency interval between a first frequency and a secondfrequency. The second frequency is greater than the first frequency.

In an embodiment of the invention, the sensing electrode and the sensingcommon electrode form a first capacitor device. The shielding layer andthe sensing electrode form a second capacitor device. The shieldinglayer and the sensing common electrode form a third capacitor device.The touch object touches the touch sensor to respectively form a fourthcapacitor device and a fifth capacitor device with the shielding layer.

In an embodiment of the invention, the sensing circuit receives areference voltage. The reference voltage is switched between a firstvoltage and a second voltage, and charges/discharges a first terminal ofthe first capacitor device to generate the relaxation signal. Therelaxation signal is oscillated between the first voltage and the secondvoltage.

In an embodiment of the invention, the sensing circuit further includesan amplifier circuit. The amplifier circuit has a first input terminal,a second input terminal and an output terminal. The first input terminalreceives the reference voltage. The output terminal is coupled to afirst terminal of the resistor device. The second input terminal iscoupled to a second terminal of the resistor device and the firstterminal of the first capacitor device.

In an embodiment of the invention, the shielding layer includes aconductive layer.

The invention provides an electronic paper display apparatus having atouch sensing function. The electronic paper display apparatus includesan electronic paper display panel. The electronic paper display panelincludes a plurality of touch sensors. Each of the touch sensorsincludes a sensing device and a sensing circuit. The sensing deviceincludes a substrate, a sensing electrode, a sensing common electrodeand a shielding layer. The sensing electrode and the sensing commonelectrode are disposed on the substrate. The shielding layer is disposedon the sensing electrode and the sensing common electrode. The sensingcircuit is electrically connected to the sensing device. The sensingcircuit includes a resistor device. A relaxation frequency of arelaxation signal of each of the touch sensors is determined accordingto a resistance of the resistor device and/or a parasitic resistance ofthe sensing device. A pulse difference of the relaxation signal ischanged by a touch object, where the touch object is a conductor. Atouch position of the touch object on the electronic paper display panelis determined by the pulse difference of the relaxation signal of eachof the touch sensors.

In an embodiment of the invention, the electronic paper displayapparatus is a segmented electronic paper display apparatus. Therelaxation frequency of the relaxation signal of each of the touchsensors is determined according to the resistance of the resistordevice.

In an embodiment of the invention, the electronic paper displayapparatus is a thin film transistor electronic paper display. Therelaxation frequency of the relaxation signal of each of the touchsensors is determined according to the resistance of the resistor deviceand the parasitic resistance of the sensing device.

The invention provides an electronic paper display panel having a touchsensing function. The electronic paper display panel includes aplurality of pixel units. The pixel units are arranged in an array. Thepixel units are electrically connected to one or a plurality of sensingcircuits. The pixel units are configured to sense a touch object. Eachof the sensing circuits includes a resistor device. A relaxationfrequency of a relaxation signal of each of the pixel units isdetermined according to a resistance of the resistor device and/or aparasitic resistance of the pixel unit. A pulse difference of therelaxation signal is changed by the touch object, where the touch objectis a conductor. A touch position of the touch object on the electronicpaper display panel is determined according to the pulse difference ofthe relaxation signal of each of the pixel units.

In an embodiment of the invention, each of the pixel units includes afirst transistor circuit and a second transistor circuit. In a displaymode, a first scan signal turns on a transistor in the first transistorcircuit, and the pixel unit performs an image display operation. In asensing mode, a second scan signal turns on a transistor in the secondtransistor circuit, and the pixel unit performs a touch sensingoperation. The second transistor circuit is electrically connected tothe first transistor circuit and the one or plurality of sensingcircuits. The second transistor circuit includes the touch capacitordevice.

In an embodiment of the invention, the touch object touches the pixelunits to form a sensing capacitor device with the pixel units, and thesecond transistor circuit further includes the sensing capacitor device.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of first scan lines and a plurality ofsecond scan lines. The first scan lines are electrically connected tothe first transistor circuits. Each of the first scan lines isconfigured to provide the first scan signal to the first transistorcircuit. The second scan lines are electrically connected to the secondtransistor circuits. Each of the second scan lines is configured toprovide the second scan signal to the second transistor circuit.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of data lines. The data lines areelectrically connected to the first transistor circuits. Each of thedata lines is configured to provide a data signal to the firsttransistor circuit. In the display mode, the transistor in the firsttransistor circuit is turned on, and the pixel unit displays image dataaccording to the data signal.

In an embodiment of the invention, the second transistor circuits areelectrically connected to the one or plurality of sensing circuitsthrough the data lines. In the sensing mode, the transistor in thesecond transistor circuit is turned on, and the one or plurality ofsensing circuits charges/discharges one terminal of the touch capacitordevice through the data lines to generate the relaxation signal.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of sensing lines. The sensing lines areelectrically connected to the second transistor circuits. The secondtransistor circuits are electrically connected to one or plurality ofsensing circuits through the sensing lines. In the sensing mode, thetransistor in the second transistor circuit is turned on, and the one orplurality of sensing circuits charges/discharges one terminal of thetouch capacitor device through the data lines to generate the relaxationsignal.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of first common electrode lines and aplurality of second common electrode lines. The first common electrodelines are electrically connected to the first transistor circuits. Eachof the first common electrode lines is configured to provide a firstcommon electrode signal to the first transistor circuit. In the displaymode, the transistor in the first transistor circuit is turned on, andthe pixel unit performs an image display operation according to thefirst common electrode signal. The second common electrode lines areelectrically connected to the second transistor circuits. Each of thesecond common electrode lines is configured to provide a second commonelectrode signal to the second transistor circuit. In the sensing mode,the transistor in the second transistor circuit is turned on, and thepixel unit performs a touch sensing operation according to the secondcommon electrode signal.

In an embodiment of the invention, each of the pixel units furtherincludes a third transistor circuit. The third transistor circuit iselectrically connected between the first transistor circuit and thesecond transistor circuit. In the display mode, a third scan signalturns on a transistor in the third transistor circuit to transmit a datasignal to the third transistor circuit, and in the display mode, thetransistor in the second transistor circuit is not turned on.

In an embodiment of the invention, in the sensing mode, the third scansignal does not turn on the transistor in the third transistor circuit,and in the sensing mode, the transistor in the second transistor circuitis turned on, and the pixel unit performs a touch sensing operation.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of third scan lines. The third scan linesare electrically connected to the third transistor circuits. Each of thethird scan lines is configured to provide the third scan signal to thethird transistor circuit. In the display mode, the third scan signalturns on the transistor in the third transistor circuit, and the pixelunit performs the image display operation.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of sensing lines. The sensing lines areelectrically connected to the second transistor circuits. The secondtransistor circuits are electrically connected to one or a plurality ofsensing circuits through the sensing lines. In the sensing mode, thetransistor in the second transistor circuit is turned on, and the one orplurality of sensing circuits charges/discharges one terminal of thetouch capacitor device through the data lines to generate the relaxationsignal.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of first common electrode lines. The firstcommon electrode lines are electrically connected to the firsttransistor circuits and the third transistor circuits. Each of the firstcommon electrode lines is configured to provide a first common electrodesignal to the first transistor circuits and the third transistorcircuits. In the display mode, transistors in the first transistorcircuits and the third transistor circuits are turned on, and the pixelunit performs the image display operation according to the first commonelectrode signal.

In an embodiment of the invention, the one or plurality of sensingcircuits respectively receive a reference voltage, and charge/dischargea first terminal of each of the touch capacitor devices to generate therelaxation signal. The reference voltage is switched between a firstvoltage and a second voltage. The relaxation signal is oscillatedbetween the first voltage and the second voltage.

In an embodiment of the invention, the sensing circuit further includesan amplifier circuit. The amplifier circuit has a first input terminal,a second input terminal and an output terminal. The first input terminalreceives the reference voltage, the output terminal is coupled to oneterminal of the resistor device, and the second input terminal iscoupled to another terminal of the resistor device and the firstterminal of the touch capacitor device.

In an embodiment of the invention, the pixel units are divided into oneor a plurality of pixel unit groups, the one or plurality of pixel unitgroups are respectively and electrically connected to one correspondingsensing circuit in the one or plurality of sensing circuits.

The invention provides an electronic paper display panel having a touchsensing function. The electronic paper display panel includes aplurality of pixel units. The pixel units are arranged in an array tosense a touch object. Each of the pixel units includes a firsttransistor, a pixel capacitor device, a storage capacitor device, asecond transistor, a touch capacitor device and a sensing capacitordevice. The first transistor has a first terminal, a second terminal anda control terminal. The first terminal of the first transistor iselectrically connected to a data line. The control terminal of the firsttransistor is electrically connected to a first scan line. The pixelcapacitor device has a first terminal and a second terminal. The firstterminal of the pixel capacitor device is electrically connected to thesecond terminal of the first transistor. The second terminal of thepixel capacitor device is electrically connected to a first commonelectrode line. The storage capacitor device has a first terminal and asecond terminal. The first terminal of the storage capacitor device iselectrically connected to the second terminal of the first transistor.The second terminal of the storage capacitor device is electricallyconnected to the first common electrode line. The second transistor hasa first terminal, a second terminal and a control terminal. The firstterminal of the second transistor is electrically connected to the dataline. The control terminal of the second transistor is electricallyconnected to a second scan line. The touch capacitor device has a firstterminal and a second terminal. The first terminal of the touchcapacitor device is electrically connected to the second terminal of thesecond transistor. The second terminal of the touch capacitor device iselectrically connected to a second common electrode line. The sensingcapacitor device has a first terminal and a second terminal. The firstterminal of the sensing capacitor device is electrically connected tothe second terminal of the second transistor. The second terminal of thesensing capacitor device is electrically connected to the second commonelectrode line. The data line is electrically connected to onecorresponding sensing circuit in one or a plurality of sensing circuits.The sensing circuit includes a resistor device. A relaxation frequencyof a relaxation signal of each of the pixel units is determinedaccording to a resistance of the resistor device and/or a parasiticresistance of the pixel unit. A pulse difference of the relaxationsignal is changed by the touch object, where the touch object is aconductor. A touch position of the touch object on the electronic paperdisplay panel is determined by the pulse difference of the relaxationsignal of each of the pixel units.

In an embodiment of the invention, each of the pixel units includes athird transistor. The third transistor has a first terminal, a secondterminal and a control terminal. The first terminal of the thirdtransistor is electrically connected to the second terminal of thesecond transistor. The second terminal of the third transistor iselectrically connected to the second terminal of the first transistor.The control terminal of the third transistor is electrically connectedto a third scan line. The first terminal of the second transistor iselectrically connected to a sensing line.

In an embodiment of the invention, the electronic paper display panelfurther includes the first scan lines, the second scan line, the datalines, the first common electrode lines and the second common electrodelines. The first scan lines, the second scan lines and the first commonelectrode lines are arranged in a first direction. The data lines andthe second common electrode lines are arranged in a second direction.

In an embodiment of the invention, the electronic paper display panelfurther includes a plurality of third scan lines and a plurality ofsensing lines. The third scan lines are arranged in the first direction.The sensing lines are arranged in the second direction.

In an embodiment of the invention, the sensing circuit receives areference voltage, and charges/discharges the first terminal of thetouch capacitor device to generate the relaxation signal. The referencevoltage is switched between a first voltage and a second voltage. Therelaxation signal is oscillated between the first voltage and the secondvoltage.

In an embodiment of the invention, the sensing circuit further includesan amplifier circuit having a first input terminal, a second inputterminal and an output terminal. The first input terminal receives thereference voltage. The output terminal is coupled to one terminal of theresistor device. The second input terminal is coupled to anotherterminal of the resistor device and the first terminal of the touchcapacitor device.

According to the above description, in the embodiments of the invention,the touch sensor includes the shielding layer, the relaxation frequencythereof is determined according to the resistance of the resistor deviceand the capacitance of the capacitor device, and is changed by the touchobject to provide good sensing quality. In an embodiment, the relaxationfrequency is determined according to the parasitic resistance and theparasitic capacitance of the pixel units, the first voltage, the secondvoltage, and parasitic resistance of a tracing on the transistorcircuit. The electronic paper display panel and the electronic paperdisplay apparatus including the touch sensor are adapted to provide thetouch sensing function.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic diagram of a touch sensor according to anembodiment of the invention.

FIG. 2 is a structural schematic diagram of a sensing device of theembodiment of FIG. 1.

FIG. 3 and FIG. 4 are respectively equivalent circuit schematic diagramsof the touch sensor of the embodiment of FIG. 1 in different operationfrequencies.

FIG. 5 is a schematic diagram of an operation frequency interval of thetouch sensor of FIG. 1 implementing a touch sensing operation.

FIG. 6 is a waveform diagram of a relaxation signal according to anembodiment of the invention.

FIG. 7 is a schematic diagram of an electronic paper display apparatusaccording to an embodiment of the invention.

FIG. 8 is a structural schematic diagram of an electronic paper displaypanel of the embodiment of FIG. 7.

FIG. 9 is a structural schematic diagram of an electronic paper displaypanel according to an embodiment of the invention.

FIG. 10 is a circuit schematic diagram of the electronic paper displaypanel of the embodiment of FIG. 9.

FIG. 11 and FIG. 12 are schematic diagrams of a pixel unit of theembodiment of FIG. 9 operated in different operation modes.

FIG. 13 is a circuit schematic diagram of an electronic paper displaypanel according to another embodiment of the invention.

FIG. 14 is a circuit schematic diagram of an electronic paper displaypanel according to another embodiment of the invention.

FIG. 15 and FIG. 16 are respectively schematic diagrams of a pixel unitof the embodiment of FIG. 14 operated in different operation modes.

FIG. 17 is a structural schematic diagram of an electronic paper displaypanel according to another embodiment of the invention.

FIG. 18 is a structural schematic diagram of an electronic paper displaypanel according to another embodiment of the invention.

FIG. 19 is a schematic diagram of an electronic paper display apparatusaccording to another embodiment of the invention.

FIG. 20 is an equivalent circuit schematic diagram of a touch sensoroperated in any frequency within an operation frequency intervalaccording to another embodiment of the invention.

FIG. 21 is a schematic diagram of a driver device according to anembodiment of the invention.

FIG. 22 is a schematic diagram of a sensing device of the embodiment ofFIG. 21.

DESCRIPTION OF EMBODIMENTS

A plurality of embodiments is provided below to describe the invention,though the invention is not limited to the provided embodiments, and theprovided embodiments may be suitably combined. A term “couple” used inthe full text of the disclosure (including the claims) refers to anydirect and indirect connections. For example, if a first device isdescribed to be coupled to a second device, it is interpreted as thatthe first device is directly coupled to the second device, or the firstdevice is indirectly coupled to the second device through other devicesor connection means. Moreover, a term “signal” refers to at least acurrent, a voltage, a charge, a temperature, data, an electromagneticwave or any other one or more signals.

FIG. 1 is a schematic diagram of a touch sensor according to anembodiment of the invention. FIG. 2 is a structural schematic diagram ofa sensing device of the embodiment of FIG. 1. FIG. 3 and FIG. 4 arerespectively equivalent circuit schematic diagrams of the touch sensorof the embodiment of FIG. 1 in different operation frequencies.Referring to FIG. 1 to FIG. 4, the touch sensor 100 of the embodiment isused for sensing a touch object 200. The touch object 200 is aconductor, for example, user's finger or a touch control device. In theembodiment, the touch sensor 100 includes a sensing device 110 and asensing circuit 120. The sensing circuit 120 is electrically connectedto the sensing device 110. The sensing circuit 120 is used forcharging/discharging the sensing device 110 to generate a relaxationsignal, and a relaxation frequency thereof is an operation frequency ofthe touch sensor 100. In the embodiment, a pulse difference of therelaxation signal of the touch sensor 100 is changed by the touch object200. When the touch object 200 touches the sensing device 110, the pulsedifference of the relaxation signal is accordingly changed. Therefore,whether the touch object 200 touches the touch sensor 100 may bedetermined according to a magnitude of the pulse difference of therelaxation signal.

To be specific, in the embodiment, the sensing device 100 includes asubstrate 112, a sensing electrode 114, a sensing common electrode 116and a shielding layer 118. The sensing electrode 114 and the sensingcommon electrode 116 are disposed on the substrate 112. The sensingelectrode 114 and the sensing common electrode 116 form a firstcapacitor device C1. In the embodiment, the sensing electrode 114 isused for transmitting a sensing signal, and the sensing common electrode116 is, for example, coupled to a ground voltage, and is used forproviding a reference voltage for a touch sensing operation. In anembodiment, the sensing common electrode 116 may also be coupled to apredetermined common electrode signal, or kept in a floating state,which is not limited by the invention. In the embodiment, the shieldinglayer 118 is disposed on the sensing electrode 114 and the sensingcommon electrode 116. The shielding layer 118 and the sensing electrode114 form a second capacitor device C2. The shielding layer 118 and thesensing common electrode 116 form a third capacitor device C3. In theembodiment, the shielding layer 118 is a transparent conductive thinfilm, for example, an Indium Tin Oxide (ITO) conductive thin film, orother similar conductive layer. In an embodiment, the shielding layer118, for example, includes a nano silver wire layer. The material andthe type of the shielding layer 118 are not limited by the invention. Inthe embodiment, the touch object 200 contacts the sensing device 110 torespectively form a fourth capacitor device C4 and a fifth capacitordevice C5 with the shielding layer 118. In the embodiment, a capacitanceof each of the capacitance devices is, for example, determined accordingto a material characteristic of each of the layers.

In the embodiment, the sensing circuit 120 includes an amplifier circuit122 and a resistor device R. The amplifier circuit 122 has a first inputterminal (a non-inverting terminal), a second input terminal (aninverting terminal) and an output terminal. The first input terminalreceives a reference voltage Vref. The output terminal is coupled to oneterminal of the resistor device R. The second input terminal is coupledto another terminal of the resistor device R and a terminal N of thefirst capacitor device C1. In the embodiment, the sensing circuit 120,for example, includes a relaxation oscillator, and a framework thereofis schematically described, and the sensing circuit 120 may beimplemented by the framework of any sensing circuit of the field, whichis not limited by the invention. Enough instructions and recommendationsfor the detailed framework and implementation method thereof may belearned from ordinary knowledge of the art, and details thereof are notrepeated.

FIG. 5 is a schematic diagram of an operation frequency interval of thetouch sensor of FIG. 1 implementing a touch sensing operation. FIG. 6 isa waveform diagram of a relaxation signal according to an embodiment ofthe invention. Referring to FIG. 3 to FIG. 6, the touch sensor 100 ofthe embodiment is, for example, operated in an operation frequencyinterval BW between a first frequency f1 and a second frequency f2,where the second frequency f2 is greater than the first frequency f1.For example, in the embodiment, the operation frequency interval BW isbetween 2 MHz and 3.6 MHz, though the invention is not limited thereto.In an embodiment, the operation frequency is substantially greater than780 KHz. In the embodiment, the touch sensor 100 is, for example,applied to an electronic paper display apparatus, as shown in FIG. 7, toperform touch sensing. In an application that the electronic paperdisplay apparatus is a segmented electronic paper display apparatus, anoperation frequency thereof is substantially greater than 750 KHz, andthe relaxation frequency of the relaxation signal of each touch sensor100 is determined according to a resistance of the resistor device R. Inan application that the electronic paper display apparatus is a thinfilm transistor electronic paper display apparatus, the operationfrequency interval BW is, for example, between 2 MHz and 3.6 MHz, andthe relaxation frequency of the relaxation signal of each touch sensor100 is determined according to the resistance of the resistor device Rand a parasitic resistance of the sensing device 110. In an embodiment,the relaxation frequency may be determined according to a parasiticresistance and a parasitic capacitance of a pixel unit, a first voltage,a second voltage, and a parasitic resistance of a tracing of atransistor circuit.

FIG. 3 is an equivalent circuit schematic diagram of the touch sensor100 operated in any frequency outside the operation frequency intervalBW. In FIG. 3, in case of any frequency outside the operation frequencyinterval BW, the fourth capacitor device C4 and the fifth capacitordevice C5 are shielded. FIG. 4 is an equivalent circuit schematicdiagram of the touch sensor 100 operated in any frequency within theoperation frequency interval BW. In FIG. 4, when the touch sensor 100 isoperated in any frequency within the operation frequency interval BW,the second capacitor device C2 and the third capacitor device C3 presenta short-circuit state.

In FIG. 4, when the touch object 200 does not touch the touch sensor100, the fourth capacitor device C4 and the fifth capacitor device C5 donot exist. In this case, the reference voltage Vref is, for example, setto the second voltage V2, and the amplifier circuit 122 charges theterminal N of the first capacitor device C1 through the resistor deviceR, and a signal waveform of the relaxation signal S is increased towardthe second voltage V2. When a voltage of the terminal N is equal to thesecond voltage V2, the reference voltage Vref is, for example, switchedto the first voltage V1, and the amplifier circuit 122 discharges theterminal N of the first capacitor device C1 through the resistor deviceR, and the signal waveform of the relaxation signal S is decreasedtoward the first voltage V1. Repeatedly, the reference voltage Vref isswitched between the first voltage V1 and the second voltage V2, andcharges/discharges the terminal N of the first capacitor device C1 togenerate the relaxation signal S. The relaxation signal S is oscillatedbetween the first voltage V1 and the second voltage V2, and in theembodiment of the segmented electronic paper display apparatus, therelaxation frequency of the relaxation signal S is determined accordingto the resistance of the resistor device R. In the embodiment of thethin film transistor electronic paper display apparatus, the relaxationfrequency of the relaxation signal S is determined according to theresistance of the resistor device R and the parasitic resistance of thesensing device 110. In an embodiment, the relaxation frequency may bedetermined according to a parasitic resistance and a parasiticcapacitance of a pixel unit, the first voltage, the second voltage, anda parasitic resistance of a tracing of a transistor circuit.

In FIG. 4, when the touch object 200 touches the touch sensor 100, thefourth capacitor device C4 and the fifth capacitor device C5 exist. Now,since an equivalent capacitance between the terminal N and the terminalground has been changed, the relaxation frequency is changed, forexample, decreased in response to the touch object 200. In a sensingperiod GT, a pulse number of the relaxation signal S is decreased.Therefore, in the embodiment, one of the methods for determining achange of the relaxation frequency is to determine whether the pulsenumber of the relaxation signal S is changed during the sensing periodGT. In other words, in the embodiment, a pulse difference of therelaxation signal S is changed by the touch object (for example, atouched conductor). Whether the touch object 200 touches the touchsensor may be determined according to the pulse difference of therelaxation signal S.

In the embodiment, one of the methods for determining whether the pulsenumber of the relaxation signal S is changed during the sensing periodGT is, for example, to transmit the relaxation signal S to a countercircuit (not shown) or other similar circuit. For example, the countercircuit is, for example, electrically connected to an output of theamplifier circuit 122 to receive the relaxation signal S, and counts thepulse number of the relaxation signal S during the sensing period GT.The counter circuit is, for example, an external circuit independent tothe sensing circuit 120, or a counter circuit configured in the sensingcircuit 120. In the embodiment, the counter circuit may be implementedby a framework of any type of the counter circuit of the technicalfield, which is not limited by the invention. Enough instructions andrecommendations for the detailed framework and implementation methodthereof may be learned from ordinary knowledge of the art, and detailsthereof are not repeated.

In the embodiment, whether the touch object 200 touches the touch sensor100 may be determined according to the pulse difference of therelaxation signal S. In an application of a plurality of touch sensors,for example, the touch sensors are arranged on a substrate in an arrayto construct a touch sensing panel. A touch position of the touch object200 on the touch sensing panel is determined by whether the pulsedifference of the relaxation signal S of each of the touch sensors ischanged.

FIG. 7 is a schematic diagram of an electronic paper display apparatusaccording to an embodiment of the invention. FIG. 8 is a structuralschematic diagram of an electronic paper display panel of the embodimentof FIG. 7. Referring to FIG. 7 and FIG. 8, the electronic paper displayapparatus 300 of the embodiment has a touch sensing function. Theelectronic paper display apparatus 300 includes an electronic paperdisplay panel 310 and a driver device 320. The driver device 320 iselectrically connected to the electronic paper display panel 310. Thedriver device 320 is used for driving the electronic paper display panel310 to display an image frame, and perform a touch sensing operation.

To be specific, in the embodiment, the electronic paper display panel310 includes a plurality of the touch sensors 100 shown in FIG. 1. InFIG. 8, the electronic paper display panel 310 includes a plurality ofsensing devices 110. The sensing circuit 120 may be disposed in thedriver device 320, or integrated with the electronic paper display panel310, or disposed in other external circuit. The configuration positionof the sensing circuit 120 is not limited by the invention. In theembodiment, the relaxation frequency of the relaxation signal of each ofthe touch sensors 110 is determined by the resistance of the resistordevice R in the sensing circuit 120 and/or the parasitic resistance inthe sensing device 110. When the touch object 200 touches the electronicpaper display panel 310, the pulse difference of the relaxation signalis changed by the touch object 200. Therefore, a touch position of thetouch object 200 on the electronic paper display panel 310 is determinedaccording to the pulse difference of the relaxation signal of each ofthe touch sensors 100. In an embodiment, the relaxation frequency mayalso be determined according to a parasitic resistance and a parasiticcapacitance of a pixel unit, a first voltage, a second voltage, and aparasitic resistance of a tracing of a transistor circuit. Moreover,enough instructions, recommendations and implementations for the touchsensing operation of the embodiment may be learned from relateddescriptions of the embodiments of FIG. 1 to FIG. 6, and details thereofare not repeated.

In the embodiment, the electronic paper display apparatus 300 is, forexample, a segmented electronic paper display apparatus or a thin filmtransistor electronic paper display apparatus, though the invention isnot limited thereto. In an embodiment, a design of the driver device 320is adjusted to be adapted to the electronic paper display apparatus 300,and the driver device 320 may be implemented by a suitable circuitframework of the technical field, which is not limited by the invention.

In the embodiment, the electronic paper display panel 310 includes theshielding layer 118. The shielding layer 118 includes an indium tinoxide conductive film, or a nano silver wire layer or other similarconductive layer, though the invention is not limited thereto. In theembodiment, the electronic paper display apparatus 300 determines thetouch position of the touch object 200 on the electronic paper displaypanel 310 according to the pulse difference of the relaxation signal ofeach of the touch sensors 100. Existence of the shielding layer 118 doesnot influence the touch sensing operation of the electronic paperdisplay apparatus 300.

FIG. 9 is a structural schematic diagram of an electronic paper displaypanel according to an embodiment of the invention. FIG. 10 is a circuitschematic diagram of the electronic paper display panel of theembodiment of FIG. 9. Referring to FIG. 9 and FIG. 10, the electronicpaper display panel 400 of the embodiment includes a plurality of firstscan lines SL1, a plurality of second scan lines SL2, a plurality ofdata lines DL1, a plurality of first common electrode lines CL1, aplurality of second common electrode lines CL2 and a plurality of pixelunits 410.

In the embodiment, the pixel units 410 are arranged in an array, and areelectrically connected to one or a plurality of sensing circuits 420through the data lines DL1. In the embodiment, the sensing circuits 420may be integrated on the electronic paper display panel 310, or disposedin other external circuit. The pixel units 410 are used for sensing thetouch object 200 of FIG. 2 or FIG. 8. In the embodiment, the pixel units410 in a same column are connected to the same sensing circuit 420. Inan embodiment, the pixel units in different columns may also beconnected to a same sensing circuit. Alternatively, in an embodiment,the pixel unit may also be properly grouped, and the pixel units of thesame group share a same sensing circuit. The number of the sensingcircuits 420 is not limited by the invention.

In the embodiment, the pixel unit 410 includes a first transistorcircuit 412 and a second transistor circuit 414. The first transistorcircuit 412 includes a first transistor Q1, a pixel capacitor device Cpand a storage capacitor device Cst. The second transistor circuit 414includes a second transistor Q2, a touch capacitor device Ctc and asensing capacitor device Cf. In the embodiment, the touch capacitordevice Ctc includes the first capacitor device C1, the second capacitordevice C2 and the third capacitor device C3 of FIG. 2. For example, thetouch capacitor device Ctc is, for example, one of the first capacitordevice C1, the second capacitor device C2 and the third capacitor deviceC3, or an equivalent capacitor device of a combination of the abovethree capacitor devices connected in series or parallel. In theembodiment, the sensing capacitor device Cf includes the fourthcapacitor device C4 and the fifth capacitor device C5 of FIG. 2. Forexample, the sensing capacitor device Cf is, for example, one of thefourth capacitor device C4 and the fifth capacitor device C5, or anequivalent capacitor device of a combination of the above two capacitordevices connected in series or parallel.

In the embodiment, a first terminal of the first transistor Q1 iselectrically connected to the data line DL1. A second terminal of thefirst transistor Q1 is electrically connected to a first terminal of thepixel capacitor device Cp and a first terminal of the storage capacitordevice Cst. A control terminal of the first transistor Q1 iselectrically connected to the first scan line SL1. A first terminal ofthe pixel capacitor device Cp is electrically connected to the secondterminal of the first transistor Q1. A second terminal of the pixelcapacitor device Cp is electrically connected to the first commonelectrode line CL1. A first terminal of the storage capacitor device Cstis electrically connected to the second terminal of the first transistorQ1. A second terminal of the storage capacitor device Cst iselectrically connected to the first common electrode line CL1. In theembodiment, the first scan line SL1 and the first common electrode lineCL1 are respectively used for providing a first scan signal and a firstcommon electrode signal to the first transistor Q1. In a display mode,the data line DL1 is used for providing a data signal to the firsttransistor Q1. The first scan signal is transmitted through the firstscan line SL1, and turns on the first transistor Q1 in the display mode,such that the pixel unit 410 performs an image display operation todisplay image data according to the data signal and the first commonelectrode signal.

In the embodiment, a first terminal of the second transistor Q2 iselectrically connected to the data line DL1. A second terminal of thesecond transistor Q2 is electrically connected to a first terminal ofthe touch capacitor device Ctc and a first terminal of the sensingcapacitor device Cf A control terminal of the second transistor Q2 iselectrically connected to the second scan line SL2. A first terminal ofthe touch capacitor device Ctc is electrically connected to the secondterminal of the second transistor Q2. A second terminal of the touchcapacitor device Ctc is electrically connected to the second commonelectrode line CL2. A first terminal of the sensing capacitor device Cfis electrically connected to the second terminal of the secondtransistor Q2. A second terminal of the sensing capacitor device Cf iselectrically connected to the second common electrode line CL2. In theembodiment, the second scan line SL2 and the second common electrodeline CL2 are respectively used for providing a second scan signal and asecond common electrode signal to the second transistor Q2. The secondscan signal is transmitted through the second scan line SL2, and turnson the second transistor Q2 in a sensing mode, such that the pixel unit410 performs a touch sensing operation to sense the touch object 200according to the second common electrode signal. In the sensing mode,the second transistor Q2 is turned on, and the sensing circuit 420charges/discharges the first terminal of the touch capacitor device Ctcthrough the data line DL1 to generate the relaxation signal S shown inFIG. 6. Moreover, enough instructions, recommendations andimplementations for the method of generating the relaxation signal S ofthe embodiment may be learned from related descriptions of theembodiments of FIG. 1 to FIG. 6, and details thereof are not repeated.

In the embodiment, the first scan lines SL1, the second scan lines SL2and the first common electrode lines CL1 are arranged in a firstdirection Y. The data lines DL1 and the second common electrode linesCL2 are arranged in a second direction X. The first direction Y and thesecond direction X are different, and are perpendicular to each other inFIG. 10.

FIG. 11 and FIG. 12 are schematic diagrams of the pixel unit of theembodiment of FIG. 9 operated in different operation modes. Referring toFIG. 11 and FIG. 12, FIG. 11 illustrates a situation that the pixel unit410 is operated in the display mode, and FIG. 12 illustrates a situationthat the pixel unit 410 is operated in the sensing mode. In FIG. 11,when the pixel unit 410 is operated in the display mode, the first scansignal turns on the first transistor Q1, and the second scan signal doesnot turn on the second transistor Q2. The data signal is transmitted tothe first transistor circuit 412 through a signal transmission path 510.The pixel unit 410 performs the image display operation to display imagedata according to the data signal and the first common electrode signal.

In FIG. 12, when the pixel unit 410 is operated in the sensing mode, thefirst scan signal does not turn on the first transistor Q1, and thesecond scan signal turns on the second transistor Q2. The sensingcircuit 420 charges/discharges the first terminal of the touch capacitordevice Ctc through the data line DL1 to generate the relaxation signal Sof FIG. 6. The relaxation signal S is transmitted through a signaltransmission path 520. In the embodiment, the relaxation frequency ofthe relaxation signal S of each of the pixel units 410 is determinedaccording to the resistance of the resistor device R and/or theparasitic resistance therein. Moreover, the pulse difference of therelaxation signal is changed by the touch object 200. When the touchobject 200 touches the pixel unit 410, the touch object 200 and thepixel unit 410 form the sensing capacitor device Cf. The touch positionof the touch object 200 on the electronic paper display panel 400 may bedetermined according to the pulse difference of the relaxation signal ofeach of the pixel units 410. In an embodiment, the relaxation frequencymay also be determined according to a parasitic resistance and aparasitic capacitance of the pixel unit, the first voltage, the secondvoltage, and a parasitic resistance of a tracing of the transistorcircuit. Moreover, enough instructions, recommendations andimplementations for the touch sensing operation of the embodiment may belearned from related descriptions of the embodiments of FIG. 1 to FIG.6, and details thereof are not repeated.

In the embodiment of FIG. 10, the second transistor circuit 414 and thefirst transistor circuit 412 share the data line DL1 to transmit therelaxation signal S, though the invention is not limited thereto. Inanother embodiment, the second transistor circuit 414 may also adoptother signal line to transmit the relaxation signal S.

FIG. 13 is a circuit schematic diagram of an electronic paper displaypanel according to another embodiment of the invention. Referring toFIG. 10 and FIG. 13, the electronic paper display panel 800 of theembodiment is similar to the electronic paper display panel 400 of theembodiment of FIG. 10, and a main difference there between is that theelectronic paper display panel 800 further includes a plurality ofsensing lines DL2, and the second transistor circuit 814 uses thesensing lines DL2 to transmit the relaxation signal S.

In detail, in the embodiment, the sensing line DL2 is electricallyconnected to the second transistor circuit 814. The second transistorcircuit 814 is electrically connected to the sensing circuit 820 throughthe sensing line DL2. In the sensing mode, the second transistor Q2 isturned on, and the sensing circuit 820 charges/discharges the firstterminal of the touch capacitor device Ctc through the sensing line DL2to generate the relaxation signal S. Moreover, enough instructions,recommendations and implementations for the touch sensing operation ofthe embodiment may be learned from related descriptions of theembodiments of FIG. 1 to FIG. 12, and details thereof are not repeated.

FIG. 14 is a circuit schematic diagram of an electronic paper displaypanel according to another embodiment of the invention. Referring toFIG. 10 and FIG. 14, the electronic paper display panel 600 of theembodiment is similar to the electronic paper display panel 400 of theembodiment of FIG. 10, and a main difference there between is that theelectronic paper display panel 600 further includes a plurality of thirdscan lines SL3 and a plurality of sensing lines DL2, and the pixel unit610 further includes a third transistor circuit 616.

To be specific, in the embodiment, the third transistor circuit 616 iselectrically connected between a first transistor circuit 612 and asecond transistor circuit 614. The third transistor circuit 616 includesa third transistor Q3. A first terminal of the third transistor Q3 iselectrically connected to the second terminal of the second transistorQ2. A second terminal of the third transistor Q3 is electricallyconnected to the second terminal of the first transistor Q1. A controlterminal of the third transistor Q3 is electrically connected to thethird scan line SL3. The first terminal of the second transistor Q2 iselectrically connected to the sensing line DL2. In the embodiment, thethird scan line SL3 and the first common electrode line CL1 arerespectively used for providing a third scan signal and the first commonelectrode signal to the third transistor Q3. In the display mode, thedata line DL1 is used for providing the data signal to the firsttransistor Q1 and the third transistor Q3. The first scan signal and thethird scan signal are transmitted through the first scan line SL1 andthe third scan line SL3, and turn on the first transistor Q1 and thethird transistor Q3 in the display mode, and the second transistor Q2 isnot turned on, such that the pixel unit 610 performs the image displayoperation to display image data according to the data signal and thefirst common electrode signal.

In the embodiment, the second scan line SL2 and the second commonelectrode line CL2 are respectively used for providing a second scansignal and a second common electrode signal to the second transistor Q2.The second scan signal is transmitted through the second scan line SL2,and turns on the second transistor Q2 in the sensing mode, and the thirdtransistor Q3 is not turned on, such that the pixel unit 610 performsthe touch sensing operation to sense the touch object 200 according tothe second common electrode signal. In the sensing mode, the secondtransistor Q2 is turned on, and the sensing circuit 620charges/discharges the first terminal of the touch capacitor device Ctcthrough the sensing line DL2 to generate the relaxation signal S of FIG.6. Moreover, enough instructions, recommendations and implementationsfor the method of generating the relaxation signal S of the embodimentmay be learned from related descriptions of the embodiments of FIG. 1 toFIG. 6, and details thereof are not repeated.

In the embodiment, the first scan line SL1, the second scan line SL2,the third scan line SL3 and the first common electrode line CL1 arearranged in the first direction Y. The data line DL1, the sensing lineDL2 and the second common electrode line CL2 are arranged in the seconddirection X. The first direction Y and the second direction X aredifferent to each other, and are perpendicular to each other in FIG. 14.

FIG. 15 and FIG. 16 are respectively schematic diagrams of the pixelunit of the embodiment of FIG. 14 operated in different operation modes.Referring to FIG. 15 and FIG. 16, FIG. 15 illustrates a situation thatthe pixel unit 610 is operated in the display mode, and FIG. 16illustrates a situation that the pixel unit 610 is operated in thesensing mode. In FIG. 15, when the pixel unit 610 is operated in thedisplay mode, the first scan signal turns on the first transistor Q1,the third scan signal turns on the third transistor Q3, and the secondscan signal does not turn on the second transistor Q2. The data signalis transmitted to the first transistor circuit 612 and the thirdtransistor circuit 616 through a signal transmission path 710. The pixelunit 610 performs the image display operation to display image dataaccording to the data signal and the first common electrode signal.

In FIG. 16, when the pixel unit 610 is operated in the sensing mode, thefirst scan signal does not turn on the first transistor Q1, the thirdscan signal does not turn on the third transistor Q3, and the secondscan signal turns on the second transistor Q2. The sensing circuit 620charges/discharges the first terminal of the touch capacitor device Ctcthrough the sensing line DL2 to generate the relaxation signal S of FIG.6. The relaxation signal S is transmitted through a signal transmissionpath 720. In the embodiment, the relaxation frequency of the relaxationsignal S of each of the pixel units 610 is determined according to theresistance of the resistor device R and/or the parasitic resistancetherein. Moreover, the pulse difference of the relaxation signal S ischanged by the touch object 200. When the touch object 200 touches thepixel unit 610, the touch object 200 and the pixel unit 610 form thesensing capacitor device Cf. The touch position of the touch object 200on the electronic paper display panel 600 may be determined according tothe pulse difference of the relaxation signal of each of the pixel units610. In an embodiment, the relaxation frequency may also be determinedaccording to a parasitic resistance and a parasitic capacitance of thepixel unit, the first voltage, the second voltage, and a parasiticresistance of a tracing of the transistor circuit. Moreover, enoughinstructions, recommendations and implementations for the touch sensingoperation of the embodiment may be learned from related descriptions ofthe embodiments of FIG. 1 to FIG. 13, and details thereof are notrepeated.

In the embodiment of FIG. 9, the electronic paper display panel 400takes the single pixel unit 410 as a basic unit for sensing the touchobject 200, though the invention is not limited thereto. In anembodiment, the pixel units may also be properly grouped, and the pixelunits of the same group may be taken as the basic unit for sensing thetouch object 200.

FIG. 17 is a structural schematic diagram of an electronic paper displaypanel according to another embodiment of the invention. The electronicpaper display panel 900 of the embodiment is similar to the electronicpaper display panel 400 of the embodiment of FIG. 9, and a maindifference there between is that the pixel units 910 of the electronicpaper display panel 900 are divided into one or a plurality of pixelunit groups 920, for example, 4 pixel unit groups. To be specific, inthe embodiment, each of the pixel unit groups 920 is electricallyconnected to the corresponding sensing circuit. For example, the pixelunit groups 920 of the same column are electrically connected to a samesensing circuit. Moreover, the pixel units 910 in each of the pixel unitgroups 920, for example, share the same sensing circuit. Moreover,enough instructions, recommendations and implementations for the touchsensing operation of the embodiment may be learned from relateddescriptions of the embodiments of FIG. 1 to FIG. 16, and detailsthereof are not repeated.

In the embodiment of FIG. 17, in view of a layout structure of theelectronic paper display panel 900, multiple columns of the pixel units910 correspond to one common electrode 930, and the common electrode 930is disposed between the groups of the pixel unit groups, though theinvention is not limited thereto. In an embodiment, the common columnmay also be disposed between the columns of the pixel units.

FIG. 18 is a structural schematic diagram of an electronic paper displaypanel according to another embodiment of the invention. The electronicpaper display panel 1000 of the embodiment is similar to the electronicpaper display panel 900 of the embodiment of FIG. 17, and a maindifference there between is that the common electrode 1030 is disposedbetween the columns of the pixel units 610. In the embodiment, the pixelunits 1010 on the electronic paper display panel 1000 of the embodimentare divided into one or a plurality of pixel unit groups 1020, forexample, 4 pixel unit groups. Each of the pixel unit groups 1020 iselectrically connected to the corresponding sensing circuit. Forexample, the pixel unit groups 1020 of the same column are electricallyconnected to a same sensing circuit. Moreover, the pixel units 1010 ineach of the pixel unit groups 1020, for example, share the same sensingcircuit. Moreover, enough instructions, recommendations andimplementations for the touch sensing operation of the embodiment may belearned from related descriptions of the embodiments of FIG. 1 to FIG.17, and details thereof are not repeated.

FIG. 19 is a schematic diagram of an electronic paper display apparatusaccording to another embodiment of the invention. Referring to FIG. 19,the electronic paper display apparatus 1100 of the embodiment has thetouch sensing function. In the embodiment, the electronic paper displayapparatus 1100 includes a driver device 1110 and an electronic paperdisplay panel 1120. The driver device 1110 is electrically connected tothe electronic paper display panel 1120. The driver device 1110 is usedfor driving the electronic paper display panel 1120 to display imageframes, and perform the touch sensing operation. A layout method of theelectrodes of the electronic paper display panel 1120 is, for example,as that shown in FIG. 17 or FIG. 18, which is not limited by theinvention.

To be specific, in the embodiment, the driver device 1110 includes ascan device 1112 and a sensing device 1114. The scan device 1112 is usedfor scanning a plurality of sensing blocks 1122 on the electronic paperdisplay panel 1120 to perform the touch sensing operation. The sensingdevice 1114 is used for controlling the scan device 1112 to scan thesensing blocks 1122, and charges/discharges each of the sensing blocks1122 to generate the relaxation signal S of FIG. 6. In the embodiment,the sensing blocks 1122 are arranged in an array, and include aplurality of columns and a plurality of rows. Each of the sensing blocks1122 includes one or a plurality of the sensing device 110 of FIG. 2.For example, a resolution of the electronic paper display panel 1120 is,for example, 320×240, and in an embodiment, every 40 columns or rowsconstruct one unit, and based on such unit, the electronic paper displaypanel 1120, for example, includes 8 sensing channels and 6 scanchannels. Therefore, the electronic paper display panel 1120 includes 48sensing blocks 1122. It should be noted that the resolution of theelectronic paper display panel 1120 and the numbers of the sensingchannels, the scan channels and the sensing blocks are only an example,and the invention is not limited thereto.

In the invention, in the driver device 1110 used for driving theelectronic paper display panel 1120, the scan device 1112 includes aplurality of scan circuits 1111, and the sensing device 1114 includes aplurality of sensing circuits 1113. The scan circuits 1111 arerespectively and electrically connected to the sensing blocks 1122 ofdifferent rows. The scan circuits 1111, for example, turn on therespectively connected sensing blocks 1122 during the sensing period GTof FIG. 6 to perform the touch sensing operation. For example, in theembodiment, one of the sensing circuits 1113_1-1113_8 (for example, thesensing circuit 1113_1) outputs a control signal Sctrl to control thescan circuits 1111_1-1111_6 based on rows to sequentially scan thesensing blocks 1122 of different rows on the electronic paper displaypanel 1120.

In the embodiment, the sensing circuits 1113 respectively andsimultaneously charge/discharge the sensing blocks 1122 of differentcolumns to generate the relaxation signal S. For example, when thesensing blocks 1122 of each row are sequentially turned on, one of thesensing circuits (for example, the sensing circuit 1113_1) outputs asynchronization signal Ssyn to synchronize the other sensing circuits1113_2-1113_8 to respectively and simultaneously charge/discharge thesensing blocks 1122 of different columns during the sensing period GT,so as to obtain the relaxation signal S of the sensing blocks 1122 ofdifferent columns.

Therefore, according to such scan sensing method, the touch position ofthe touch object on the electronic paper display panel 1120 may bedetermined. For example, when the sensing block 1122_33 is touched, ahorizontal coordinate position (a first orientation) of the touch objecton the electronic paper display panel 1120 may be determined accordingto a position of the sensing circuit 1113_3 (located at a third column),and a vertical coordinate position (a second orientation) of the touchobject on the electronic paper display panel 1120 may be determinedaccording to a position of the scan circuit 1111_3 (located at a thirdrow). In the embodiment, the electronic paper display panel 1120 mayimplement a single-point or multi-point touch sensing operation, andenough instructions, recommendations and implementations for theoperation method thereof may be learned from ordinary knowledge of thefield, and details thereof are not repeated.

Therefore, in the embodiment, the sensing device 1114, for example,charges/discharges each of the sensing blocks 1122 according to thefirst voltage V1 and the second voltage V2 of FIG. 6 to generate therelaxation signal S. The pulse difference of the relaxation signal S ischanged by the touch object. The touch position of the touch object onthe electronic paper display panel 1120 is determined according to thepulse difference of the relaxation signal S of each of the sensingblocks 1122. Moreover, enough instructions, recommendations andimplementations for the touch sensing operation of the embodiment may belearned from related descriptions of the embodiments of FIG. 1 to FIG.8, and details thereof are not repeated.

In the embodiment, the circuit structure of the electronic paper displaypanel 1120 is, for example, as that shown in FIG. 10, which is a circuitstructure where the two transistors share the data line to transmit therelaxation signal. Alternatively, the circuit structure of theelectronic paper display panel 1120 is, for example, as that shown inFIG. 13, which is a circuit structure where the two transistors do notshare the data line to transmit the relaxation signal. Alternatively,the circuit structure of the electronic paper display panel 1120 is, forexample, as that shown in FIG. 14, which is a circuit structure wherethe three transistors share the data line to transmit the relaxationsignal, or other similar circuit structure. The circuit structure of theelectronic paper display panel 1120 is not limited by the invention.

In the embodiment, a circuit structure of the sensing circuit 1113 maybe the same or similar with that of the sensing circuit 120 of FIG. 4.The circuit structure of the sensing circuit 1113 is not limited by theinvention. In the embodiment, the sensing circuit 1113, for example,includes a counter circuit (not shown). The counter circuit is used forsetting the sensing period GT to receive the relaxation signal S. Thecounter circuit counts a pulse number of the relaxation signal S duringthe sensing period. In the embodiment, the counter circuit is, forexample, an external circuit different to the sensing circuit 113, or acounter circuit configured in internal of the sensing circuit 1113.

In an embodiment, each of the sensing circuits 1113 may be implementedby a single microcontroller or other similar device, for example, afield-programmable gate array (FPGA). The microcontroller, for example,includes a function of a relaxation oscillator, a function of thecounter circuit, etc. The microcontroller further outputs the controlsignal Sctrl and the synchronization signal Ssyn to respectively controlthe scan operation of the scan circuits 1111 and synchronize the sensingoperations of the other sensing circuits 1113.

In the embodiment, enough instructions, recommendations andimplementations for the circuit structure and the implementation of thescan circuits 1111 may be learned from ordinary knowledge of the field,and details thereof are not repeated.

FIG. 20 is an equivalent circuit schematic diagram of a touch sensoroperated in any frequency within an operation frequency intervalaccording to another embodiment of the invention. Referring to FIG. 4and FIG. 20, the touch sensor 2100 of the embodiment is similar to thetouch sensor 100 of the embodiment of FIG. 4, and a main differencethere between lies in a circuit structure of a sensing circuit 2120. Inthe embodiment, a sensing block 2110, for example, includes one or aplurality of the sensing devices 110 shown in FIG. 2, so that aschematic diagram of an equivalent capacitance thereof is similar asthat shown in FIG. 4.

To be specific, in the embodiment, the sensing circuit 2120 includes aresistor device R, a latch circuit 222, a first comparator circuit 224and a second comparator circuit 226. The resistor device R has a firstterminal and a second terminal. The second terminal of the resistordevice R is coupled to the sensing block 2110. The latch circuit 222 hasa first input terminal, a second input terminal and an output terminal.The output terminal of the latch circuit 222 is coupled to the firstterminal of the resistor device R. In an embodiment, the latch circuit222, for example, includes a RS latch, and the first input terminal, thesecond input terminal and the output terminal thereof are respectively areset terminal, a setting terminal and a Q terminal of a RS flip-flop.The first comparator circuit 224 has a first input terminal, a secondinput terminal and an output terminal. The first input terminal of thefirst comparator circuit 224 is coupled to the second terminal of theresistor device R and the sensing block 2210. The second input terminalof the first comparator circuit 224 receives the first voltage V1. Theoutput terminal of the first comparator circuit 224 is coupled to thefirst input terminal of the latch circuit 222. The second comparatorcircuit 226 has a first input terminal, a second input terminal and anoutput terminal. The first input terminal of the second comparatorcircuit 226 receives the second voltage V2. The second input terminal ofthe second comparator circuit 226 is coupled to the second terminal ofthe resistor device R and the sensing block 2210. The output terminal ofthe second comparator circuit 226 is coupled to the second inputterminal of the latch circuit 222.

Referring to FIG. 6 and FIG. 20, in the embodiment, when the touchobject 200 touches the sensing block 2110, if a voltage of a node N issmaller than the first voltage V1, the second voltage V2 charges thefirst capacitor device C1 until the voltage of the node N is greaterthan the second voltage V2. When the voltage of the node N is greaterthan the second voltage V2, the first capacitor device C1 dischargestoward the first voltage V1 until the voltage of the node N is smallerthan the first voltage V1. Repeatedly, the relaxation signal S isproduced at the node N, as shown in FIG. 6. When the touch object 200touches the sensing block 2110, the fourth capacitor device C4 and thefifth capacitor device C5 exist. In this case, since an equivalentcapacitance of the node N to the ground terminal has been changed, thepulse difference of the relaxation signal S is changed (for example,decreased) by the touch object 200. During the sensing period GT, thepulse number of the relaxation signal S is decreased. Therefore, in theembodiment, one of the methods for determining whether the relaxationfrequency is changed is to, for example, determine whether the pulsenumber of the relaxation signal S is changed during the sensing periodGT. In other words, in the embodiment, the pulse difference of therelaxation signal S is changed by the touch object. Whether the touchobject 200 touches the sensing block 2110 is, for example, determinedaccording to the pulse difference of the relaxation signal S.

Enough instructions, recommendations and implementations for the touchsensing operation of the embodiment may be learned from relateddescriptions of the embodiments of FIG. 1 to FIG. 6, and details thereofare not repeated. Moreover, in the embodiment of FIG. 19, the circuitstructure of the sensing circuit 1113 is, for example, the same orsimilar to the sensing circuit 2120 of FIG. 20. The circuit structure ofthe sensing circuit 1113 is not limited by the invention.

FIG. 21 is a schematic diagram of a driver device according to anembodiment of the invention. Referring to FIG. 21, the driver device 230of the embodiment is, for example, an integrated chip. The driver device230 includes a touch driving block 232 and a display driving block 234.The display driving block 234 is electrically connected to the touchdriving block 232. In the embodiment, the scan device and the sensingdevice are disposed in the touch driving block 232.

To be specific, in the embodiment, the display driving block 234includes a display driver, a first common electrode voltage controlcircuit, a first gate control circuit and a display data controlcircuit. The first common electrode voltage control circuit is, forexample, coupled to the first common electrode lines CL1 of FIG. 10,FIG. 13 or FIG. 14, and is used for controlling supplying of the firstcommon electrode signals. The first gate control circuit is, forexample, coupled to the first scan lines SL1 of FIG. 10, FIG. 13 or FIG.14, and is used for controlling a conduction state of the firsttransistor Q1 according to the first scan signal. The display datacontrol circuit is, for example, coupled to the data line DL1 of FIG. 10or FIG. 13, or the data line DL1 of FIG. 14. The display data controlcircuit is used for controlling the data signal written to the firsttransistor Q1 or the third transistor Q3. Therefore, the pixel unitperforms the image display operation to display image data according tothe data signal. The display driver is used for driving and controllingthe electronic paper display panel to perform the image displayoperation. The display driver includes various circuit devices requiredfor driving the electronic paper display panel.

In the embodiment, the touch driving block 232 includes a scan device, asensing device, a processor circuit, a counter circuit, a voltagegenerator circuit, a second common electrode voltage control circuit anda second gate control circuit (pixel control circuit). One of theimplementations of the scan device and the sensing device is as thatshown in FIG. 19, which is not limited by the invention. The scan deviceis, for example, coupled to the second scan lines SL2 of FIG. 10, FIG.13 or FIG. 14. The sensing device is, for example, coupled to the datalines DL1 of FIG. 10 and the sensing lines DL2 of FIG. 13.

In the embodiment, the voltage generator circuit, for example, includesone or a plurality of programmable voltage sources, and is used forgenerating the first voltage V1 and the second voltage V2. The countercircuit is used for setting the sensing period GT, and counts the pulsenumber of the relaxation signal S of the node N. In an embodiment, thecounter circuit may include two counters to execute the above twooperation steps. For example, one of the counters is used for countingthe pulse number of the relaxation signal S, and another counter is usedfor setting the sensing period GT. The second common electrode voltagecontrol circuit is, for example, coupled to the second common electrodelines CL2 of FIG. 10, FIG. 13 or FIG. 14, and is used for controllingsupplying of the second common electrode signals. The second gatecontrol circuit is, for example, coupled to the third scan lines SL3 ofFIG. 14, and is used for controlling a conduction state of the thirdtransistor Q3 according to the third scan signal. In an embodiment, thesecond gate control circuit is selectively configured. For example, whenthe driver device 230 is used for driving the electronic paper displaypanels 400, 800 of FIG. 10 and FIG. 13, since the circuit structures ofthe electronic paper display panels 400, 800 do not include the thirdtransistor Q3, in this case, the driver device 230 is not configuredwith the second gate control circuit. In the embodiment, the processorcircuit is, for example, used for receiving a sensing result of thesensing device, and calculates a touch position of the touch object onthe electronic paper display panel according to the relaxation signal Sof the sensing block. Enough instructions, recommendations andimplementations for the touch sensing operation of the embodiment may belearned from related descriptions of the embodiments of FIG. 1 to FIG.20, and details thereof are not repeated.

In the embodiment, designs of the display driver, the first commonelectrode voltage control circuit, the first gate control circuit, thedisplay data control circuit, the processor circuit, the voltagegenerator circuit, the second common electrode voltage control circuitand the second gate control circuit are adjusted along with differentelectronic paper display panels, and are implemented by proper circuitstructures of the technical field, which are not limited by theinvention.

In the embodiment, the devices or circuits included in each of theblocks in the integrated chip are only an example, and are not intendedto be limiting of the invention, and may be adaptively adjusted by adesigner according to an actual requirement.

FIG. 22 is a schematic diagram of a sensing device of the embodiment ofFIG. 21. Referring to FIG. 21 and FIG. 22, the sensing device 2214 ofthe embodiment includes a plurality of sensing circuits 2220 and aplurality of selector circuits 2230. The sensing circuits 2220 areconnected to corresponding sensing channels. The selector circuits 2230are used for synchronously selecting the first voltage V1 or the secondvoltage V2, and transmitting the selected voltage to amplifier circuits2222. Therefore, the voltage received by the amplifier circuits 2222 maybe switched between the first voltage V1 and the second voltage V2.Enough instructions, recommendations and implementations for theoperation of the sensing device 2214 may be learned from relateddescription of the embodiment of FIG. 19, and details thereof are notrepeated.

In summary, in the embodiments of the invention, the driver device ofthe electronic paper display panel is used for scanning the sensingblocks, and charging/discharging the sensing blocks of different columnsto perform the touch sensing operation. The driver device includes aplurality of sensing circuits or a plurality of microprocessors toperform the touch sensing operation. The driver device may be integratedinto an integrated chip to drive the electronic paper display panel toperform the touch sensing operation. In the embodiments of theinvention, the sensing block includes one or a plurality of touchsensors. The touch sensor includes a shielding layer. Existence of theshielding layer does not influence the touch sensing operation of thetouch sensor. Whether the touch object touches the touch sensor may bedetermined according to the pulse difference of the relaxation signal.Moreover, the electronic paper display panel and the electronic paperdisplay apparatus including the touch sensor may provide the touchsensing function. The touch position of the touch object on the touchsensing panel may be determined according to whether the pulsedifference of the relaxation signal of each touch sensor is changed.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of theinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the invention covermodifications and variations of this invention provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. A touch sensor, adapted to sense a touch object, the touch sensor comprising: a sensing device, comprising a substrate, a sensing electrode, a sensing common electrode and a shielding layer, wherein the sensing electrode and the sensing common electrode are disposed on the substrate, and the shielding layer is disposed on the sensing electrode and the sensing common electrode; and a sensing circuit, electrically connected to the sensing device, and comprising a resistor device, wherein a relaxation frequency of a relaxation signal of the touch sensor is determined according to a resistance of the resistor device and/or a parasitic resistance of the sensing device, and a pulse difference of the relaxation signal is changed by the touch object, wherein the touch object is a conductor.
 2. The touch sensor as claimed in claim 1, wherein the touch sensor is operated in an operation frequency interval between a first frequency and a second frequency, and the second frequency is greater than the first frequency.
 3. The touch sensor as claimed in claim 1, wherein the sensing electrode and the sensing common electrode form a first capacitor device, the shielding layer and the sensing electrode form a second capacitor device, the shielding layer and the sensing common electrode form a third capacitor device, and the touch object touches the touch sensor to respectively form a fourth capacitor device and a fifth capacitor device with the shielding layer.
 4. The touch sensor as claimed in claim 3, wherein the sensing circuit receives a reference voltage, and the reference voltage is switched between a first voltage and a second voltage, and charges/discharges a first terminal of the first capacitor device to generate the relaxation signal, wherein the relaxation signal is oscillated between the first voltage and the second voltage.
 5. The touch sensor as claimed in claim 4, wherein the sensing circuit further comprises an amplifier circuit having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal receives the reference voltage, the output terminal is coupled to a first terminal of the resistor device, and the second input terminal is coupled to a second terminal of the resistor device and the first terminal of the first capacitor device.
 6. The touch sensor as claimed in claim 1, wherein the shielding layer comprises a conductive layer.
 7. An electronic paper display apparatus, having a touch sensing function, and the electronic paper display apparatus comprising: an electronic paper display panel, comprising a plurality of touch sensors, wherein each of the touch sensors comprises: a sensing device, comprising a substrate, a sensing electrode, a sensing common electrode and a shielding layer, wherein the sensing electrode and the sensing common electrode are disposed on the substrate, and the shielding layer is disposed on the sensing electrode and the sensing common electrode; and a sensing circuit, electrically connected to the sensing device, and comprising a resistor device, wherein a relaxation frequency of a relaxation signal of each of the touch sensors is determined according to a resistance of the resistor device and/or a parasitic resistance of the sensing device, a pulse difference of the relaxation signal is changed by a touch object, wherein the touch object is a conductor, and a touch position of the touch object on the electronic paper display panel is determined by the pulse difference of the relaxation signal of each of the touch sensors.
 8. The electronic paper display apparatus as claimed in claim 7, wherein the electronic paper display apparatus is a segmented electronic paper display apparatus, and the relaxation frequency of the relaxation signal of each of the touch sensors is determined according to the resistance of the resistor device.
 9. The electronic paper display apparatus as claimed in claim 7, wherein the electronic paper display apparatus is a thin film transistor electronic paper display, and the relaxation frequency of the relaxation signal of each of the touch sensors is determined according to the resistance of the resistor device and the parasitic resistance of the sensing device.
 10. An electronic paper display panel, having a touch sensing function, and the electronic paper display panel comprising: a plurality of pixel units, arranged in an array, electrically connected to one or a plurality of sensing circuits, and configured to sense a touch object, wherein each of the pixel units comprises a touch capacitor device, and each of the sensing circuits comprises a resistor device, wherein a relaxation frequency of a relaxation signal of each of the pixel units is determined according to a resistance of the resistor device and/or a parasitic resistance of the pixel unit, a pulse difference of the relaxation signal is changed by the touch object, wherein the touch object is a conductor, and a touch position of the touch object on the electronic paper display panel is determined according to the pulse difference of the relaxation signal of each of the pixel units.
 11. The electronic paper display panel as claimed in claim 10, wherein each of the pixel units comprises: a first transistor circuit, wherein in a display mode, a first scan signal turns on a transistor in the first transistor circuit, and the pixel unit performs an image display operation; and a second transistor circuit, wherein in a sensing mode, a second scan signal turns on a transistor in the second transistor circuit, and the pixel unit performs a touch sensing operation, wherein the second transistor circuit is electrically connected to the first transistor circuit and the one or plurality of sensing circuits, and the second transistor circuit comprises the touch capacitor device.
 12. The electronic paper display panel as claimed in claim 11, wherein the touch object touches the pixel units to form a sensing capacitor device with the pixel units, and the second transistor circuit further comprises the sensing capacitor device.
 13. The electronic paper display panel as claimed in claim 11, further comprising: a plurality of first scan lines, electrically connected to the first transistor circuits, and each of the first scan lines being configured to provide the first scan signal to the first transistor circuit; and a plurality of second scan lines, electrically connected to the second transistor circuits, and each of the second scan lines being configured to provide the second scan signal to the second transistor circuit.
 14. The electronic paper display panel as claimed in claim 11, further comprising: a plurality of data lines, electrically connected to the first transistor circuits, and each of the data lines being configured to provide a data signal to the first transistor circuit, wherein in the display mode, the transistor in the first transistor circuit is turned on, and the pixel unit displays image data according to the data signal.
 15. The electronic paper display panel as claimed in claim 14, wherein the second transistor circuits are electrically connected to the one or plurality of sensing circuits through the data lines, and in the sensing mode, the transistor in the second transistor circuit is turned on, and the one or plurality of sensing circuits charges/discharges one terminal of the touch capacitor device through the data lines to generate the relaxation signal.
 16. The electronic paper display panel as claimed in claim 14, further comprising: a plurality of sensing lines, electrically connected to the second transistor circuits, wherein the second transistor circuits are electrically connected to one or plurality of sensing circuits through the sensing lines, and in the sensing mode, the transistor in the second transistor circuit is turned on, and the one or plurality of sensing circuits charges/discharges one terminal of the touch capacitor device through the data lines to generate the relaxation signal.
 17. The electronic paper display panel as claimed in claim 11, further comprising: a plurality of first common electrode lines, electrically connected to the first transistor circuits, and each of the first common electrode lines being configured to provide a first common electrode signal to the first transistor circuit, wherein in the display mode, the transistor in the first transistor circuit is turned on, and the pixel unit performs an image display operation according to the first common electrode signal; and a plurality of second common electrode lines, electrically connected to the second transistor circuits, and each of the second common electrode lines being configured to provide a second common electrode signal to the second transistor circuit, wherein in the sensing mode, the transistor in the second transistor circuit is turned on, and the pixel unit performs a touch sensing operation according to the second common electrode signal.
 18. The electronic paper display panel as claimed in claim 11, wherein each of the pixel units comprises: a third transistor circuit, electrically connected between the first transistor circuit and the second transistor circuit, wherein in the display mode, a third scan signal turns on a transistor in the third transistor circuit to transmit a data signal to the third transistor circuit, and in the display mode, the transistor in the second transistor circuit is not turned on.
 19. The electronic paper display panel as claimed in claim 18, wherein in the sensing mode, the third scan signal does not turn on the transistor in the third transistor circuit, and in the sensing mode, the transistor in the second transistor circuit is turned on, and the pixel unit performs a touch sensing operation.
 20. The electronic paper display panel as claimed in claim 18, further comprising: a plurality of third scan lines, electrically connected to the third transistor circuits, and each of the third scan lines being configured to provide the third scan signal to the third transistor circuit, wherein in the display mode, the third scan signal turns on the transistor in the third transistor circuit, and the pixel unit performs the image display operation.
 21. The electronic paper display panel as claimed in claim 18, further comprising: a plurality of sensing lines, electrically connected to the second transistor circuits, and the second transistor circuits being electrically connected to one or a plurality of sensing circuits through the sensing lines, wherein in the sensing mode, the transistor in the second transistor circuit is turned on, and the one or plurality of sensing circuits charges/discharges one terminal of the touch capacitor device through the data lines to generate the relaxation signal.
 22. The electronic paper display panel as claimed in claim 18, further comprising: a plurality of first common electrode lines, electrically connected to the first transistor circuits and the third transistor circuits, and each of the first common electrode lines being configured to provide a first common electrode signal to the first transistor circuits and the third transistor circuits, wherein in the display mode, transistors in the first transistor circuits and the third transistor circuits are turned on, and the pixel unit performs the image display operation according to the first common electrode signal.
 23. The electronic paper display panel as claimed in claim 10, wherein the one or plurality of sensing circuits respectively receive a reference voltage, and charge/discharge a first terminal of each of the touch capacitor devices to generate the relaxation signal, and the reference voltage is switched between a first voltage and a second voltage, wherein the relaxation signal is oscillated between the first voltage and the second voltage.
 24. The electronic paper display panel as claimed in claim 23, wherein the sensing circuit further comprises an amplifier circuit having a first input terminal, a second input terminal and an output terminal, the first input terminal receives the reference voltage, the output terminal is coupled to one terminal of the resistor device, and the second input terminal is coupled to another terminal of the resistor device and the first terminal of the touch capacitor device.
 25. The electronic paper display panel as claimed in claim 10, wherein the pixel units are divided into one or a plurality of pixel unit groups, the one or plurality of pixel unit groups are respectively and electrically connected to one corresponding sensing circuit in the one or plurality of sensing circuits.
 26. An electronic paper display panel, having a touch sensing function, and the electronic paper display panel comprising: a plurality of pixel units, arranged in an array, and configured to sense a touch object, wherein each of the pixel units comprises: a first transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the first transistor is electrically connected to a data line, and the control terminal of the first transistor is electrically connected to a first scan line; a pixel capacitor device, having a first terminal and a second terminal, wherein the first terminal of the pixel capacitor device is electrically connected to the second terminal of the first transistor, and the second terminal of the pixel capacitor device is electrically connected to a first common electrode line; a storage capacitor device, having a first terminal and a second terminal, wherein the first terminal of the storage capacitor device is electrically connected to the second terminal of the first transistor, and the second terminal of the storage capacitor device is electrically connected to the first common electrode line; a second transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the second transistor is electrically connected to the data line, and the control terminal of the second transistor is electrically connected to a second scan line; a touch capacitor device, having a first terminal and a second terminal, wherein the first terminal of the touch capacitor device is electrically connected to the second terminal of the second transistor, and the second terminal of the touch capacitor device is electrically connected to a second common electrode line; and a sensing capacitor device, having a first terminal and a second terminal, wherein the first terminal of the sensing capacitor device is electrically connected to the second terminal of the second transistor, and the second terminal of the sensing capacitor device is electrically connected to the second common electrode line, wherein the data line is electrically connected to one corresponding sensing circuit in one or a plurality of sensing circuits, the sensing circuit comprises a resistor device, a relaxation frequency of a relaxation signal of each of the pixel units is determined according to a resistance of the resistor device and/or a parasitic resistance of the pixel unit, and a pulse difference of the relaxation signal is changed by the touch object, wherein the touch object is a conductor, and a touch position of the touch object on the electronic paper display panel is determined by the pulse difference of the relaxation signal of each of the pixel units.
 27. The electronic paper display panel as claimed in claim 26, wherein each of the pixel units comprises: a third transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal of the third transistor is electrically connected to the second terminal of the second transistor, the second terminal of the third transistor is electrically connected to the second terminal of the first transistor, the control terminal of the third transistor is electrically connected to a third scan line, and the first terminal of the second transistor is electrically connected to a sensing line.
 28. The electronic paper display panel as claimed in claim 26, further comprising the first scan lines, the second scan line, the data lines, the first common electrode lines and the second common electrode lines, wherein the first scan lines, the second scan lines and the first common electrode lines are arranged in a first direction, and the data lines and the second common electrode lines are arranged in a second direction.
 29. The electronic paper display panel as claimed in claim 28, further comprising a plurality of third scan lines and a plurality of sensing lines, wherein the third scan lines are arranged in the first direction, and the sensing lines are arranged in the second direction.
 30. The electronic paper display panel as claimed in claim 26, wherein the sensing circuit receives a reference voltage, and charges/discharges the first terminal of the touch capacitor device to generate the relaxation signal, and the reference voltage is switched between a first voltage and a second voltage, wherein the relaxation signal is oscillated between the first voltage and the second voltage.
 31. The electronic paper display panel as claimed in claim 30, wherein the sensing circuit further comprises an amplifier circuit having a first input terminal, a second input terminal and an output terminal, the first input terminal receives the reference voltage, the output terminal is coupled to one terminal of the resistor device, and the second input terminal is coupled to another terminal of the resistor device and the first terminal of the touch capacitor device. 